I. Field of the Invention
The present invention relates generally to the construction and use of interlocking and layered elements to form a protective shield against shoreline erosion.
II. Description of Prior Art
Shoreline erosion is one of the foremost concerns of persons living in coastal regions. The natural movement of water over beaches, shorelines, lakes and ponds leads inexorably to the deterioration of the land, which presents a variety of serious problems for nearby residents, commercial fisherman and farmers, and sportsmen. Repairs to these shorelines can be quite expensive, often costing millions of dollars in the case of public beaches and coastal areas. Even in small areas controlled by private property owners, the costs and effort to arrest the continuous erosion of the land can be excessive.
A wide variety of revetment structures or systems to control erosion have been developed with varying degrees of success. Some approaches rely upon large sheets of interlocking blocks strung together with cables, which are laid upon the shoreline by heavy machinery, such as that shown in U.S. Pat. No. 4,201,494. Other methods employ large numbers of "lock" blocks 20 having cavities formed along their perimeters which are connected to one another by "key" blocks, as depicted in U.S. Pat. No. 4,372,705. Still others, as illustrated by U.S. Pat. No. 5,020,938, require blocks having portions which overlap but which do not interlock.
From a review of the foregoing patents and others related to them, there is a need for an erosion control system for shorelines that uses a standard block or element to construct substantially the entire system. Moreover, it would be desirable for those elements to overlap and interlock with one another to provide the maximum protection for the underlying soil, while being less subject to theft and vandalism. Also, there is a need for such an erosion control system that can be constructed by starting from the upper region of the shoreline and working down to the waterline. The elements to such a shoreline protection system should be relatively inexpensive to manufacture and simple to install with little or no training or expertise.